This is to say that Blankenhorn — a long-standing opponent of same-sex marriage — has shifted his energies to saving the institution of marriage, regardless of whom one chooses as a mate.

If you’re unfamiliar with Blankenhorn, it is because he hasn’t been barking his positions on television the way so many ideologues do. And this may be because he is not strictly an ideologue but one of those rare people who agonize in search of the right thing.

As creator of the Institute for American Values, Blankenhorn initially sought to avoid the issue of gay marriage because itwas so divisive — and because opposition necessarily meant hurting friends and often, family. Eventually, he wrote a book against same-sex marriage and testified against it as California’s Proposition 8 was challenged in court.

Then, last summer, he changed his mind.

On Tuesday, Blankenhorn and more than 70 diverse signatories released a letter urging Americans to end the war over gay marriage and change the question from “Should gays marry?” to “How can we save marriage?” Joining Blankenhorn are scholars, law professors, theologians and journalists, notably his former archrivalJonathan Rauch. Whether one is straight or gay, they say, the challenge is to figure out how to strengthen marriage for the broader benefit to society.

Blankenhorn’s journey through the marriage minefield parallels that of many Americans who, though they held no animosity toward gays, weren’t sure that changing the institution of marriage was in society’s best interest.

Like Blankenhorn, my greatest concern has been the effect on our nation’s children. The operative questions, posed so well by traditional marriage warrior Maggie Gallagher, were: Do we want to codify the notion that one parent, either the mother or father, is dispensable? And, what effect might this have?

We have witnessed the fallout from broken families as divorce and out-of-wedlock births have skyrocketed in recent decades. These trends have been wrought not by expanding the definition of marriage but by a general lowering of respect for the institution. Blankenhorn’s group suggests that, given Americans’ evolving acceptance of same-sex marriage, we should refocus our energies on a goal that transcends sexual orientation.

His group’s focus is on the disintegration of marriage in the middle and lower classes, which, they say, is creating a new underclass of inequality. As it happens, well-educated people tend to stay married in greater numbers, while the less educated — high school and no college — are becoming a subculture of economically depressed, single-parent families. Studies no longer need to be cited to convince us of what we know: Children from such homes have a lousy shot at the pursuit of happiness.

Blankenhorn still believes, as do most Americans, that a child benefits most from a loving mother and father committed in marriage. The U.N. Convention on the Rights of the Childeven has designated this arrangement as a right. “Marriage,” Blankenhorn has written, “is a gift that society bestows on its children.”

But this gift has been badly damaged or, too often these days, withheld. Moreover, many same-sex couples today also have children. It is simply not possible to justify offering societal protections to only certain children. As Blankenhorn has recognized, it is in everyone’s best interest that all children in all families have the security of parents committed through marriage with all its attendant rights and responsibilities.

In an op-ed last summer, Blankenhorn expanded on his vision: “Once we accept gay marriage, might we also agree that marrying before having children is a vital cultural value that all of us should do more to embrace?” he asked. “Can we agree that, for all lovers who want their love to last, marriage is preferable to cohabitation?

“Can we discuss whether both gays and straight people should think twice before denying children born through artificial reproductive technology the right to know and be known by their biological parents?”

Now there’s a feast for thought.

Blankenhorn’s personal transformation has resulted in a welcome shift in the public debate. How clever of him to recognize that his allies in strengthening marriage are the very people who for so long have been excluded.